2-D Collisions

1)        A falling ball hits the ground at a speed of 6.5 m/s. It has a mass of 0.84 kg. After it hits the ground, it bounces upward at a speed of 3.9 m/s. How much impulse was required to make the ball bounce?

2)        A soccer player (that’s football to the rest of the world) kicks the ball, initially at rest. Explain whether momentum of the system is conserved and the forces involved for these three systems: (a) the ball, (b) the ball and the player’s kicking leg, (c) the ball and the entire player.

3)        A physics student is playing pool. Feeling ambitious, he decides to calculate the momentum of all 16 balls after the break. The mass of each ball is 0.16 kg. Before the collision, the cue ball is moving at 13 m/s at an angle 3.5° from straight. Find the total momentum immediately after the break.

4)        Two objects collide in a frictionless world. Before the collision, the first object moves at 37.0 m/s directly along the x-axis. Its mass is 15.0 kg. It collides with a 25.0 kg object initially at rest. After the collision, the 15.0 kg object moves at 22.0 m/s, 19° above the x-axis, and the 25.0 kg object moves at an angle 24° below the x-axis. What is the speed of the second object?

5)        Another physics student is playing pool. She shoots the cue ball straight down the table, where it hits a second ball (the “object ball”). The masses are the same for each ball. The cue ball goes to the left at 3.0 m/s, 25° from straight, and the object ball goes right at 2.0 m/s, 39° from straight. Find the initial velocity of the cue ball.

6)        A 10.0 kg rock slides across ice at 4.0 m/s, 10.0° east of north. It collides with a 6.5 kg rock at rest. After the collision, the 10.0 kg rock moves due north at 2.25 m/s. What is the velocity of the 6.5 kg rock?